added closing tab syntax to overview article

Author: ericd-mst-github

articles/virtual-machines/image-builder-overview.md

@@ -112,7 +112,7 @@ Register-AzProviderPreviewFeature -ProviderNamespace Microsoft.VirtualMachineIma
 ```azurecli-interactive
 az feature register --namespace Microsoft.VirtualMachineImages --name FairfaxPublicPreview
 ```
-
+---
 
 To access the Azure VM Image Builder public preview in the China North 3 region, you must register the *Microsoft.VirtualMachineImages/MooncakePublicPreview* feature. To do so, run the following command in either PowerShell or Azure CLI:
 
@@ -127,6 +127,7 @@ Register-AzProviderPreviewFeature -ProviderNamespace Microsoft.VirtualMachineIma
 ```azurecli-interactive
 az feature register --namespace Microsoft.VirtualMachineImages --name MooncakePublicPreview
 ```
+---
 
 ## OS support